Power transmitting toothed belts, also known as timing belts, are used for many applications, like driving an engine's camshaft off the crankshaft. The teeth of the belt mesh with corresponding teeth on pulleys mounted the shaft members to prevent slippage and provide synchronized rotation of the driven shaft member (e.g. camshaft) with respect to the driving shaft member (e.g. crankshaft). Such timing belts are lighter in weight than metal power transmission chains and are able to be used in applications requiring the use of small pulleys having small arcs of contact with the belt. At present, however, such timing belts are costly to produce which is believed in part to be attributed to the present process used to manufacture the timing belts namely molding.
Apparatus for cutting teeth into an endless belt blank to produce a timing belt comprises belt support means for supporting the endless blank for selective rotation about a first axis, a cutting wheel having a plurality of peripheral tooth cutting portions spaced laterally from one another, and wheel rotation means for rotating the wheel about a second axis that is transverse to the first axis and translating means for translating the wheel relative to said belt support means across the width of the belt blank along a path generally parallel to the first axis for cutting a plurality of transverse teeth into the belt blank with the tooth cutting portions.
According to another aspect of the invention, a grinding wheel construction for cutting teeth into a belt blank to produce a timing belt comprises a wheel having an axis of rotation and an abrasive peripheral grinding surface of predetermined width, wherein the grinding surface has a concave profile across its width and a plurality of laterally spaced grinding ribs extending circumferentially about the periphery of the grinding surface.
According to yet another aspect of the invention, a method of producing a timing belt comprises the steps of: (a) supporting a belt blank about a first axis with a peripheral surface of the belt blank disposed outwardly; (b) rotating the cutting wheel about a second axis that is transverse to the first axis and translating the wheel along a path and across the outwardly disposed peripheral surface to thereby cut a plurality of teeth into the belt blank extending across the width of the belt in circumferentially spaced relation to one another; (c) indexing the belt blank rotatably about the first axis to bring another uncut portion of the belt blank into the cutting path of the wheel; and (d) repeating steps (c) and (d) until the entire outwardly disposed periphery of the belt blank has been provided with teeth.
The invention enables timing belts to be produced from uncut belt blank stock by cutting the teeth into the belt blank stock to produce the timing belts, at a recognized cost, time, and labor savings over the presently molded timing belts.